Dalio is founder of the Westport-based Bridgewater Associates, the biggest hedge fund in the world. He is ranked No. 29 on the list with a net worth of $15.3 billion. That's up from No. 30 on last year's list.

Next up for Connecticut is Steve Cohen at No. 37. Cohen, another Greenwich resident, is worth $12 billion. Cohen now manages his personal fortune through Point 72 Asset Management. He was forced to shut down his hedge fund, SAC Capital, after pleading guilty to insider-trading charges. His fortune took a hit in that case: He paid out $1.8 billion to cover SAC's penalties.

The other billionaires making that Top 400 cut are:

No. 114: Paul Tudor Jones II of Greenwich with $4.7 billion. He is the founder of the Tudor Investment Corp.

No. 129: Karen Pritzker of Branford with $4.3 billion. She inherited family money from hotels and has grown her fortune through investments.

No. 171: Peter Buck of Danbury worth $3.5 billion. He is co-founder of Doctor's Associates, the parent company of Subway. In 2014, he made a $30 million donation to Danbury Hospital.

As for the nation, the richest American is still Bill Gates, worth $76 billion from Microsoft. Cracking the Top 10 this year for the first time is another tech guy: Facebook founder Mark Zuckerberg, worth $40.3 billion, according to Forbes.

What did it take to make the list this year? The bottom cut-off was $1.7 billion, the highest in the history of the list, Forbes said.